Genetic Interactions Reveal that Specific Defects of Chloroplast Translation are Associated with the Suppression of var2‐Mediated Leaf Variegation. Issue 10 (10th September 2013)

• Record Type: Journal Article
• Authors: Liu, Xiayan; Zheng, Mengdi; Wang, Rui; Wang, Ruijuan; An, Lijun; Rodermel, Steve R.; Yu, Fei
• Is Part Of: Journal of integrative plant biology. Volume 55:Issue 10(2013)
• Page Start: 979
• Page End: 993
• Publication Date: 2013-09-10
• Subjects: Plants -- Periodicals; Plants -- China -- Periodicals; Electronic journals; 580.5
• DOI: 10.1111/jipb.12078
• Languages: English
• ISSNs: 1672-9072

Abstract

<abstract abstract-type="main" xml:lang="en"> <title>Abstract</title> <sec id="jipb12078-sec-0001" sec-type="section"> <p> <italic>Arabidopsis thaliana</italic> L. <italic>yellow variegated</italic> (<italic>var2</italic>) mutant is defective in a chloroplast FtsH family metalloprotease, AtFtsH2/VAR2, and displays an intriguing green and white leaf variegation. This unique <italic>var2</italic>‐mediated leaf variegation offers a simple yet powerful tool for dissecting the genetic regulation of chloroplast development. Here, we report the isolation and characterization of a new <italic>var2</italic> suppressor gene, <italic>SUPPRESSOR OF VARIEGATION8</italic> (<italic>SVR8</italic>), which encodes a putative chloroplast ribosomal large subunit protein, L24. Mutations in <italic>SVR8</italic> suppress <italic>var2</italic> leaf variegation at ambient temperature and partially suppress the cold‐induced chlorosis phenotype of <italic>var2</italic>. Loss of SVR8 causes unique chloroplast rRNA processing defects, particularly the 23S–4.5S dicistronic precursor. The recovery of the major abnormal processing site in <italic>svr8</italic> 23S–4.5S precursor indicate that it does not lie in the same position where SVR8/L24 binds on the ribosome. Surprisingly, we found that the loss of a chloroplast ribosomal small subunit protein, S21, results in aberrant chloroplast rRNA processing but not suppression of <italic>var2</italic> variegation. These findings suggest that the disruption of specific aspects of chloroplast translation, rather than a general impairment in chloroplast translation, suppress <italic>var2</italic> variegation and the existence of complex genetic interactions in chloroplast development.</p> </sec> </abstract>